In general, NS means achromatic and transparent salt solution having about 0.9 w/v % of the salinity, which is the same amount of osmotic pressure to man's body fluid and 4.5 to 8.0 of pH range. Especially, NS filtered and sterilized is used for washing rhinitis patients' noses and cleansing and sterilizing contact lens.
NS is manufactured as illustrated in FIG. 1. The manufacturing procedure is divided into sterilizing step S1 sterilizing a large amount of distilled water by heating water under approximate 121° C. with high pressure for about 30 minutes, a step S2 making saline water which has the same osmotic pressure to man's body fluid by put sodium chloride (NaCl) into sterilized distilled water as an osmotic pressure controller, a step S3 which put pH buffer agents to adjust acidity within pH 6.5 to 8.0, a step S4 which put antiseptic to limit the propagation of bacteria, a filtering step S5 to remove the impurities and a step S6 which pack the filtered normal saline solution in a container.
In the sterilizing step S1, the distilled water should be heated with high pressure and temperature.
In the step 2 S2, medicinal potassium chloride KCl can be used as an osmotic controller instead of medicinal sodium chloride and the salinity is adjusted to about 0.9 w/v %, the same salinity to man's body fluid.
The step 3 S3 is to adjust pH of NS to the range of man's body fluid by putting ph buffer agents such as boric acid, citrate, phosphoric acid.
The distilled water sterilized by high temperature and pressure keeps sterilized condition at the time of manufacturing, however, it can be deteriorated as time goes by. To prevent the propagation of bacteria, antiseptic such as solvate, dymed have been used.
Such conventional NS has been accomplished by sterilizing with high pressure and temperature. Unfortunately, with these procedures, a special container which can endure such high pressure and temperature should be required to sterilize NS and it can be only acquired by professional manufacturer so that general users or consumers cannot directly make and use NS because they do not afford to have the appropriate sterilizing apparatus under these conventional technology.
In other words, the professional manufacturer has manufactured a large amount of NS using a big container. Thus, manufactured with this procedure, NS has been packed in a relatively big size over 1 l in order to satisfy the consumer's convenience and the proper packing cost. However, NS packed in such a big package get easily contaminated after opening its package. In order to use fresh NS, user should use it up within 3˜4 days after opening the package. In spite of the importance of uncontaminated condition of NS, users go on using it after passing 3˜4 days without discarding the rest of NS. Therefore, it causes users to use contaminated NS. Furthermore, the antiseptic used to prevent the propagation of bacteria causes allergies for several users.
For these reasons, needs for using fresh NS have been increased.
On the other hand, contact lenses which directly contact with eyes are easily contaminated by residues from eyes and foreign substances from outside, and clean washing of the lenses is the important way to prevent the contamination. Therefore, these needs for making contact lenses clean by washing them well lead many studies on the effective cleansing method of contact lenses.
“Contact lens cleansing and sterilizing apparatus” Korea patent application No. 279,074 conceived by Lim, Sung Muk offered cleansing and sterilization of contact lenses in a cleansing apparatus with NS using ultrasonic wave generated by a vibrator and ultraviolet lamp. However, sterilization using ultraviolet wave by electrical vibration causes damage to contact lenses of hard type, and therefore, its use is limited to contact lenses of soft type.
Also, the sterilization using ultraviolet wave is not enough to remove bacteria and viruses attached on the surface of contact lenses or living in a normal saline solution.
Thus, the needs for easily portable contact lenses washer with excellent cleansing and sterilizing power which can be used regardless of a contact lens type and remove bacteria and viruses are increasing.